A large proportion (some estimates are as high as 25%) of the electricity generated in the United States each year goes to lighting. Accordingly, there is an ongoing need to provide lighting that is more energy-efficient. It is well-known that incandescent light bulbs are very energy-inefficient light sources. About 90% of the electricity they consume is released as heat rather than light. Fluorescent light bulbs are more efficient than incandescent light bulbs (e.g., by a factor of about 10) but are still less efficient as compared to solid state light emitters, such as light emitting diodes.
In addition, as compared to the normal lifetimes of solid state light emitters, e.g., light emitting diodes, incandescent light bulbs have relatively short lifetimes, typically about 750-1,000 hours. In comparison, light emitting diodes, for example, have typical lifetimes between 50,000 and 70,000 hours. Fluorescent bulbs have yet longer lifetimes (e.g., 10,000-20,000 hours) than incandescent lights, but provide less favorable color reproduction.
Color reproduction is typically measured using the Color Rendering Index (CRI Ra), which is a relative measure of the shift in surface color of an object when lit by a particular lamp. CRI Ra is a modified average of the measurements of how the color rendition of an illumination system compares to that of a reference radiator when illuminating eight reference colors. The CRI Ra equals 100 if the color coordinates of a set of test colors being illuminated by the illumination system are the same as the coordinates of the same test colors being irradiated by the reference radiator. Daylight has a high CRI (Ra of approximately 100), with incandescent bulbs also being relatively close (Ra greater than 95), and fluorescent lighting being less accurate (typical Ra of 70-80). Certain types of specialized lighting have very low CRI Ra. For example, mercury vapor or sodium lamps have Ra as low as about 40 or even lower. Another challenge facing the development of new lighting systems is how to achieve a high CRI.
Another issue faced by conventional light fixtures is the need to periodically replace the lighting devices (e.g., light bulbs, etc.). Such issues are particularly problematic where access is difficult (e.g., vaulted ceilings, bridges, high buildings, traffic tunnels, etc.) and/or where change-out costs are extremely high. The typical lifetime of conventional fixtures is about 20 years, corresponding to a light-producing device usage of at least about 44,000 hours (e.g., based on usage of 6 hours per day for 20 years). Light-producing device lifetime is typically much shorter, thereby creating the need for periodic change-outs. Thus, a further challenge lies in achieving a long lifetime so as to reduce the amount of downtime.
Designs have been provided in which existing LED component packages and other electronics are assembled into a fixture. In such designs, a packaged LED is mounted to a circuit board mounted to a heat sink, and the heat sink is mounted to the fixture housing along with required drive electronics. In many cases, additional optics (secondary to the package parts) are also needed to produce uniform illumination. Short of the optics, LEDS behave as point sources that fan out the light. LEDS especially at the die level are Lambertian in nature.
The expression “light emitting diode” is sometimes used to refer to the basic semiconductor diode structure (e.g., the chip). The commonly recognized and commercially available “LED” that is sold (for example) in electronics stores typically represents a “packaged” device made up of a number of parts. These packaged devices typically include a semiconductor based light emitting diode such as (but not limited to) those described in U.S. Pat. Nos. 4,918,487; 5,631,190; and 5,912,477 (each incorporated herein by reference in its entirety), various wire connections, and a package that encapsulates the light emitting diode.
In substituting light emitting diodes for other light sources, e.g., incandescent light bulbs, packaged LEDs have been used with conventional light fixtures, for example, fixtures that include a hollow lens and a base plate attached to the lens, the base plate having a conventional socket housing with one or more contacts that is/are electrically coupled to a power source. For example, LED light bulbs that comprise an electrical circuit board, a plurality of packaged LEDs mounted to the circuit board, and a connection post attached to the circuit board and adapted to be connected to the socket housing of the light fixture, whereby the plurality of LEDs can be illuminated by the power source, have been constructed.
FIG. 1 is a molded, flexible silicone rubber untinted, diffused light guide array 102 usable in connection with LED light sources. The FIG. 1 example may be used, for example, in connection with backlighting keypads and indicator windows, e.g., in front panel assemblies. Differently sized and/or shaped light pipe elements 104, 106, and 108 may be provided in the light guide array 102. LED lamps may fit against the bases of the solid light pipe elements 104, 106, and 108, or fit inside hollow light pipe elements. The light pipe array 102 may be placed over an LED lamp PC board assembly to form a backlighting unit.
FIG. 2 is a simplified view of a LED lighted panel assembly 200. This internally lighted panel uses HLMP-650X untinted, non-diffused, SMT subminiature LED lamps 202 surface mounted on a double-sided PC board 204. Maximum metalization is used on both sides to achieve a low thermal resistance to ambient, and metallization vias 206 are shown in FIG. 2. The LED lamps 202 are distributed throughout the panel (which includes a glass substrate 208) to achieve a desired lighting effect. Light rays from the LED lamps 202 blend together within the panel to produce a somewhat more even illumination through the illuminated areas on the face of the panel 200. These illuminated areas are diffused and coated with a thin layer of translucent white paint. In daylight, the LED lamps 202 are off, and the illumination areas 210 appear white by reflecting ambient light. At night, these areas are internally illuminated by the LED lamps 202 and appear the same color as the LED light. The exterior surfaces of the panel 200 are painted with a white reflecting paint, leaving open the areas on the face of the panel to be internally illuminated. An overcoat of black, scratch resistant paint is added to form the exterior finish 212. The overall thickness of the panel is 5.84 mm.
Although the development of light emitting diodes has in many ways revolutionized the lighting industry, some of the characteristics of light emitting diodes have presented challenges, some of which have not yet been fully met. For example, the emission spectrum of any particular light emitting diode is typically concentrated around a single wavelength (as dictated by the light emitting diode's composition and structure), which is desirable for some applications, but not desirable for others, e.g., for providing lighting, such an emission spectrum provides a very low CRI Ra.
Thus, it will be appreciated that there is a need in the art for an improved light source/fixture that overcomes one or more of these and/or other difficulties, and/or method of making the same.
In certain example embodiments, a method of making a coated article including a substrate supporting a coating is provided. A titanium-based precursor is provided. A chelate is provided. The titanium-based precursor is reacted with the chelate to form a chelated titanium-inclusive substance. An organic resin material is provided. The chelated titanium-inclusive substance is cross-linked with the organic resin material to form an organic-inorganic hybrid solution. The organic-inorganic hybrid solution is disposed on the substrate in forming the coating.
In certain example embodiments, a method of making a coated article including a substrate supporting a coating is provided. An organic-inorganic hybrid solution is provided, with the organic-inorganic hybrid solution having been made by: reacting a titanium- and/or zirconium-based precursor with a chelate to form a chelated substance, and cross-linking the chelated substance with an organic material to form the organic-inorganic hybrid solution. Either (a) the organic-inorganic hybrid solution is wet applied on the substrate, or (b) the organic-inorganic hybrid solution is introduced into a carrier medium and then the carrier medium is extruded onto the substrate. The organic-inorganic hybrid solution is cured once disposed on the substrate.
In certain example embodiments, a method of making an electronic device is provided. A substrate is provided. At least one light emitting diode (LED) is disposed on the substrate. An organic-inorganic hybrid solution is provided, with the organic-inorganic hybrid solution having been made by: reacting a titanium- and/or zirconium-based precursor with a chelate to form a chelated substance, and cross-linking the chelated substance with an organic material to form the organic-inorganic hybrid solution. Either (a) the organic-inorganic hybrid solution is wet applied on the substrate over the at least one LED, or (b) the organic-inorganic hybrid solution is introduced into a carrier medium and then the carrier medium is extruded onto the substrate over the at least one LED. The organic-inorganic hybrid solution is cured once disposed on the substrate.
In certain example embodiments, a device is provided. A first substrate is provided. A mirror is supported by the first substrate. A printed circuit board supports a plurality of light emitting diodes (LEDs)/A second substrate is provided. A laminate is supported by a first major surface of the second substrate that faces the printed circuit board supporting the plurality of LEDs. The laminate is formed from a first organic-inorganic hybrid solution, with the laminate having an index of refraction of at least about 1.8.
In certain example embodiments, a device is provided. A first glass substrate is provided. A thin-film mirror coating is supported by the first substrate. A flexible printed circuit (FPC) supports a plurality of light emitting diodes (LEDs) flip-chip mounted thereto. A second glass substrate is provided. A laminate is supported by a first major surface of the second substrate that faces the printed circuit board supporting the plurality of LEDs, with the laminate laminating together the first and second substrates.
In certain example embodiments, a device is provided. A first glass substrate is provided. A thin-film mirror coating is supported by the first substrate. A flexible printed circuit (FPC) supports a plurality of light emitting diodes (LEDs) flip-chip mounted thereto. A polymer-based insulator layer is interposed between the mirror and the FPC, with the insulator layer being formed from a first organic-inorganic hybrid solution. A second glass substrate is provided. A laminate is supported by a first major surface of the second substrate that faces the printed circuit board supporting the plurality of LEDs, with the laminate laminating together the first and second substrates.
In certain example embodiments, a method of making an LED device is provided. A substrate is provided. A plurality of LEDs is formed on the substrate. A random pattern is created on the LEDs and/or in one or more layers of the LEDs, with the random pattern having a light scattering effect on light produced by the LEDs. In certain example embodiments, an LED device is provided.
According to certain example embodiments, the random pattern may be created by: generating a fractal pattern, with the fractal pattern being a random fractal pattern or having randomness introduced thereto; and transferring the generated fractal pattern onto one or more layers of the LEDs.
According to certain example embodiments, the random pattern may be created by: providing an aqueous solution of nano- or micron-scale elements; and disposing the solution to an area, directly or indirectly, on the LEDs to randomly disperse the elements on the LEDs.
In certain example embodiments, a device is provided. First and second glass substrates are provided, with the first and second substrates being substantially parallel and spaced apart so as to define a cavity therebetween. A plurality of pillars is disposed between the first and second substrates. An edge seal is provided around the periphery of the first and/or second susbtrate(s). At least one conductive bus bar is disposed on an inner surface of the second substrate facing the first substrate. At least one n-leg and at least one p-leg is in contact with the at least one bus bar. At least one conductor connects the at least one n-leg and the at least one p-leg. At least one LED supported by the at least one conductor. In certain example embodiments, a method of making the same is provided.
In certain example embodiments, a device is provided. First and second glass substrates are provided, with the first and second substrates being substantially parallel and spaced apart so as to define a cavity therebetween. A plurality of pillars is disposed between the first and second substrates. An edge seal is provided around the periphery of the first and/or second susbtrate(s). At least one conductive bus bar is disposed on an inner surface of the second substrate facing the first substrate. A plurality of thermoelectric (TE) modules is in contact with the at least one bus bar, with each said TE module including an n-leg and p-leg connected to one another via a conductor. A plurality of ILEDs is disposed on conductors of the plurality of TE modules. In certain example embodiments, a method of making the same is provided.
The features, aspects, advantages, and example embodiments described herein may be combined in any suitable combination or sub-combination to realize yet further embodiments.